The performance of UV/H2O2, UV/O-3, and UV/H2O2/O-3 oxidation systems for the treatment of municipal solid-waste landfill leachate was investigated. Main objective of the experiment was to remove total organic carbon (TOC), non-biodegradable organic compounds (NBDOC) and color. In UV/H2O2 oxidation experiment, with the increase of H2O2 dosage, removal efficiencies of TOC and color along with the ratio of biochemical oxygen demand (BOD) to chemical oxygen demand (COD) of the effluent were increased and a better performance was obtained than the system H2O2 alone. In UV/H2O2 oxidation, under the optimum condition H2O2 (0.2 time), removal efficiencies of TOC and color were 78.9% and 95.5%, respectively, and BOD/COD ratio was significantly increased from 0.112 to 0.366. In UV/O-3 oxidation, with the increase of O-3 dosage, removal efficiencies of TOC and color along with BOD/COD ratio of the effluent were increased and a better performance was obtained than the system O-3 alone. Under the optimum condition UV/O-3 (50 mg-min(-1)), removal efficiencies of TOC and color were 61.0% and 87.2%, respectively, and BOD/COD ratio was significantly increased from 0.112 to 0.323. In UV/H2O2/O-3 system, color removal and BOD/COD ratio were improved further and TOC removal efficiency was found to be 30.4% higher than the system UV/O-3 without H2O2.